The ex-tend-it RS-232 Extender extends your RS-232 device up to 1000 feet away from your computer. The RS-232 Extender sender unit sits next to your computer. The RS-232 sender is powered by a 5-volt power supply, which also powers the receiver side. The RS-232 cables connect to the source to the RS-232 sender. At the extended location, the RS-232 device is connected to the RS-232 Extender receive unit. CAT-5 cables connect the send and receive units - up to 1000 feet away.